Nice interview with Janie Bryant the costume designer for Mad Men.
The money quote is this:
Now the woman behind the Mad Men phenomenon has disclosed how the show’s unique style was created.Janie Bryant, the show’s costume designer, says it's all down to shapewear. Or what the lingerie department calls foundation garments. Girdles and longline bras - a cross between a bra and a corset - reform Mad Men's female bodies into hourglass shapes. And when the antique and reproduction bras and garters cause the actresses too much pain, assistants provide them with pads of moleskin to cushion their skin.
I say it all the time, but so many customers just do not want to hear it...if you are going to wear vintage you need to have the right foundation garments.